Lift jack



J. FURST.

LIFT JACK.

APPLICATION FILED JUNE 23, 1920.

2 SHEETS-SHEET 1- 1,420,831, 4 Patented June 27,1922.

.l. FURST.

LIFT JACK.

APPLICATION FILED JUNE 23, 1920.

2 SHEETS-SHEET 2.

'M'Enessen Patented June 27, 1922.

JAKOBFT TRST, 0F ZURICH, SWITZERLAND.

' LIFT JACK.

To all whom it may concern Be it known that I, Janos Fr'insr, a citizen of the Swiss Confederation, residing at Zurich, in the Swiss Confederation, have invented new and useful Improvements in Lift Jacks (for which Ihave filed an ap plication in Germany, June 21, 1919, No. 44,790 x1/35), of which the following is a specification.

This invention relates to lift-jacks and its object is to provide an external plunger or lift-rod with parallelogrammic link-motion articulated to the supporting post, while the operating hand lever is pivoted on another post or otherwise movably connected with a support in such a manner as to spread the weight lifted over the two posts without complicating the operation or rendering same difficult.

A single hand-lever serves for lifting the weight upon the lift-rod pivoted to said lever and connected by a link to the pivotstandard or supporting post thereof, while a pivoted rest is secured to the lever so as to automatically fall into position at the lifting of said lever and to be reversed by a previously tensioned spring when the weight is to be lowered to its normal position.

I attain my object by the mechanical device shown in the accompanying drawings, in which:

Figures 1 and 2 are side elevations of the lifting-jack in two different positions; Fig. 3 is a plan of Fig. 2; Fig. 4 shows in side view separately the jack and the folded hand-lever; Figs. 5 and 6 are side elevations, showing different positions of a modified lifting-jack; Figs. 7 and 8 are side elevations of a further modified lifting-jack.

Referring first to Figs. 1 to 4, the liftrod a is pivotally carried near the pivoted end of the hand-lever composed of the parts Z), f, g, and carrying a pivoted rest 2'. The lift-rod a has a parallelogrammic motion with reference to the supporting post 01 by reason of the articulated parts 6 and c in connection with the post (Z. The hand-lever has its part b detachably secured by a with drawable pin 6, while the parts 7 and g of the same have an articulated joint so as to render this part of the lever foldable for storing. Fig. 4 shows the lifting-jack taken to pieces ready to be placed in a tool box or the like. To the part f of the hand-lever Specification-cf Letters Patent Patented June 27, 1922. Application filecl June 23,

1920. Serial No. 391,198.

is pivoted the rest 2' which can fold alongside of said part f when the jack is not in use.

For a lifting operation, the partsof the jack are positioned as shown in Fig. 1, then the hand-lever is raised as shown in Fig. 2, whereby the rest 2' is permitted to fall by its own weight so as to sustain the hand-lever.

Thus, the weight is jointly carried on the.

post d and the rest 2'.

To ensure the automatic folding up of the rest 71 in order to lower the weight, a spring is with a pull under control of an operating lever Z is here provided; the dotted position of lever Z in Fig. 2, clearly explains the action of the spring-pull. After the jack is placed in position and before raising the hand-lever, the spring-controlling lever Z is turned over into position shown by full lines in Figs. 1 and 2 so as to release the pull on the rest 2' and allow the latter to drop.

To lower the-weight, the lever Z is turned as is indicated by the arrow on in Fig. 2 so as to tension the'spring is, the hand-lever is then slightly raised so as to allow the spring is to pull back and fold the rest 2' against the handlever, whereafter the latter can be lowered with the weight as shown in Fig. 1.

After each lowering of the hand-lever, the small lever Z should be turned into the posi tion shown by full lines so that the spring 76 may not prevent the dropping of the rest 2' at a subsequent lifting operation. Naturally the lever Zis so hinged and arranged as to securely remain in both end positions after being definitely operated.

In the modification shown in Figs. 5 and 6, the parts a and d and the lower link connecting same with the post 03, are formed as in the previous form, while the hand-lever has its three parts foldably assembled by two articulated joints. The rest consists of a hinged toothed portion 2' pivoted on the hand-lever, and of a spur m fast on the base plate n of the post (Z, the spur'm engaging the teeth of i for supporting the handlever under weight. A spring is can be tensioned by a lever Z to pull 2' out of engagement in order that the hand-lever may be lowered. If desired, a spring may be pro-- vided to assist in keeping the parts i and m in engagement as long as is required.

In the modification shown in Figs. 7 and 8 the only difierence to that shown in Figs.

the hand-lever, and a spring and tensioning device for folding up said rest against the hand-lever.

2. In a lifting-jack, a supporting post, a foldable hand-lever pivoted to said post, a lifting rod pivotally carried on the handlever, a link pivotally connecting the lifting rod with the said supporting post, a rest pivoted to the hand-lever, a spur fast on the base plate of the said Supporting post for engagement With said pivoted rest, and a spring and tensioning device for folding said rest against the hand-lever.

JAKOB Miner. 

